Harare: Zimbabwe is being ruled by a military junta and 66 supporters of the opposition MDC have been killed in political violence since disputed March elections, opposition leader Morgan Tsvangirai said on Tuesday.

"This country is effectively being run by a military junta, 66 people have been killed and 200 unaccounted for," Tsvangirai told a news conference in Harare.

Meanwhile, ruling ZANU-PF party defector Simba Makoni said that the June 27 presidential run-off election should be called off because a free and fair vote is impossible.

Makoni, who challenged President Robert Mugabe in disputed March elections, said opposition MDC leader Morgan Tsvangirai must negotiate a transitional government to rule for five years.

The second round follows a disputed March 29 election in which official results showed Tsvangirai beat Mugabe, but not by enough votes to avoid a run-off.